Microsoft is working to resolve an ongoing and widespread Microsoft 365 outage impacting multiple services and features, including Exchange Online, Microsoft Teams, and SharePoint Online.

Since this outage started about six hours ago, Downdetector has received thousands of reports, with affected users saying they are also experiencing problems connecting to other services, such as OneDrive, Purview, Copilot and Outlook Web and Desktop.

“We are investigating an issue impacting users attempting to access Exchange Online or functionality within the Microsoft Teams calendar. For more information, please refer to MO941162 in the admin center,” the company said when it acknowledged the issues six hours ago.

“As we continue to work to resolve the issue, we have added a comprehensive list of affected services and scenarios to the more information section.”

In the admin center incident report, Microsoft confirmed that the outage will prevent customers from accessing Exchange Online through Outlook on the web, the Outlook desktop client, Representational State Transfer (REST), and Exchange ActiveSync (EAS).

The company also says some customers may experience issues performing actions within Microsoft Fabric, Microsoft Bookings, and Microsoft Defender for Office365.

While Remond only shared that the outage was caused by a “recent change,” the company has already implemented a fix for the affected infrastructure, restarted the affected systems and is monitoring the situation.

“We have begun deploying the fix currently being deployed across the affected environment. As this progresses, we will begin manually restarting a subset of machines that are in an unhealthy state,” Microsoft said an hour ago.

“We are monitoring the progress of the fix, which has been deployed in approximately 60% of affected environments. We are continuing to manually restart the remaining affected machines.”

Microsoft’s Office Service Status and Microsoft 365 Network Status pages currently show no issues with the company’s network health and availability, ISP availability, or customer network infrastructure.

In July, another global outage disabled multiple Microsoft 365 and Azure services, including the admin center, Intune, Entra, Power BI, and Power Platform services.

A day later, the company admitted that the nine-hour outage was caused by a distributed denial-of-service (DDoS) attack.